Detector for highway vehicle traffic



Feb. 11, 1958 E. J. SCHULENBURG 2,823,279

DETECTOR FOR HIGHWAY VEHICLE TRAFFIC Filed Sept. 15, 1954 53 50 M as J5; INVENTOR. JQZ/ar d J fic/zule United States Patent 9 DETECTOR FOR HEGHWAY VEHICLE TRAFFIC Edward J. Schulenburg, Danvilie, Ill.

Application September 13, 1954, Serial No. 455,643

Claims. (Cl. 200-86) This invention is directed to a detector for highway vehicle trafiic which may be placed. across a highway for providing an electrical contact as thewheels of the vehicles pass thereover. The detector of this invention may be utilized in connection with substantially any type of traffic system, such as indicator, counter, alarm, speed and traific control systems, and the like.

The principal object of this invention is to provide an improved detector to be placed across the highway wherein the need for external electrical contacts or switches is eliminated, wherein the need for enclosed pressure tubes for operating pressure operated switches is eliminated, wherein the electrical contacts are arranged within the detector itself to be directly actuated by the wheels of the vehicles passing thereover, wherein the detector doesnot take the weight of the vehicle passing thereover, wherein positive and fool proof operation is assured, wherein it may be quickly and permanently installed in a highway, and wherein it may be simplyand inexpensively manufactured.

Further objects of this invention reside in the details of construction of the detector and in the cooperative relationships between the component parts thereof.

Other objects and advantages of this invention will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawing,

in which:

Fig. 1 is a perspective view of a section of a highway with the detector of this invention installed therein;

Fig. 2 is a vertical sectional view through the detector of this invention taken substantially along the line 2-2 of Fig. 1;

Fig. 3 is a vertical sectional view through the hollow tube of flexible resilient insulating material before the contact strips are mounted therein;

Fig. 4 is a vertical sectional view similar to Fig. 2 but illustrating the detector being depressed by the wheel of a vehicle passing thereover.

The detector of this invention is generally designated at 10 and is shown installed in a highway 11 in Fig. 1. As shown more clearly in Figs. 2 and 4 the detector includes an upwardly facing channel member 12 which may be a conventional iron channel section. This channel member 12 includes a web portion 13 and upwardly extending flange portions 14. The channel member 12 is installed in the highway 11 by cutting a transverse groove in the highway to a depth corresponding to the height of the channel member and then inserting the channel member in the transverse groove. The transverse groove is illustrated at 15 in Figs. 2 and 4. In this way, the channel member 12 is permanently installed in the highway.

A flexible resilient tube 17 of electrical insulating material is laid in the channel member 12. This tube 17 has side walls 18 and a bottom wall 19 which conform to the configuration of the channel member 12 so as to be firmly supported thereby. The tube 17 also has a top wall 20 which protrudes above the channel member 12 and hence the highway 11. Preferably this top wall 20 of the tube is arched slightly. The tube 17 is hollow throughout its length as indicated at 21. The tube 17 may be made of any suitable flexible resilient electrical insulating material such as rubber, synthetic rubber, neoprene and the like.

The tube 17 is internally provided with a pair of opposed downwardly facing shoulders 22, a pair of opposed inwardly and upwardly extending fingers 23 above the shoulders 22, and a pair of opposed inwardly and up-- wardly extending fingers 24 below the shoulders 22.. The fingers 23 and 24 being integrally formed in the tube 3.7 are likewise flexible and resilient and have electrical insulating properties. These fingers 23 and 24 normally assume the positions illustrated in Fig. 3, these being the tree positions thereof. The tube 17 may be formed in any suitable manner such as by extrusion molding which is a particularly inexpensive method.

An upper metallic contact strip 25 is interposed between the top wall 20 and the upper fingers 23 and due to the resiliency of these fingers the metallic contact strip 23 is maintained adjacent the top wall 20. This contact strip 25 may be formed of any suitable material such as copper, brass or the like and it is provided with a plurality of contacts 26 depending downwardly therefrom. These contacts 26 may be spaced at intervals alongthe contact strip 25 and also may be made of any suitable electrical conducting material. A lower metallic contact strip 27 is interposed between the shoulders 22 and thelower fingers 24 and due to the resiliency of the lower fingers 24 the metallic contact strip 27 is normally maintained in engagement with the shoulders 22. The contact strip 27 may be formed of the same material as the contact strip 25 and it is provided with a plurality of contacts 28 which extend upwardly in vertical alignment with the contacts 26. The contacts 26 and 28 are normally spaced apart as indicated in Fig. 2, this spacing being maintained by the shoulders 22 and the fingers 23 and 24.

When a vehicle passes over the detector 10, as illustrated in Fig. 4, the wheel 29 of the vehicle depresses the top wall 20 of the tube 17. This causes the upper contact strip 25 and its contacts 26 to move downwardly so that the contacts 26 electrically contact the contacts 28 carried by the lower contact strip 27. The contact strip 27 being resiliently supported by the fingers 24 may also move downwardly when the contacts 26 engage the contacts 28. This downward movement of the contact strip 27 operates as a strain release to prevent undue pressure being applied to the contact strips 25 and 27 and the contacts 26 and 28. Thus it is impossible to overload the contact strips 25 and 27 and the contacts 26 and 28 and damage thereto from overloading is eliminated. Movement of the contacts 26 into engagement with the contacts 28 by the vehicle as illustrated in Fig. 4 completes an electrical circuit between the contact srtips 25 and 27 which circuit may be extended by conductors 30 leading to a suitable control box 31 of a trafiic system. The ends of the tube 17 may be sealed against water and moisture so as to prevent deterioration of the electrical contacts 26 and 28 and the contact strips 25 and 27. When the vehicle passes by the detector the tube 17 by its own resiliency expands to its normal condition as illustrated in Fig. 2 for separating the electrical contacts 26 and 28.

The contact strips 25 and 27 along with their contacts 26 and 28 may be readily inserted lengthwise into the tube 17 prior to the closing or sealing the ends thereof. This provides for a simple and inexpensive assembly procedure. If desired, the tube 17 may be cemented into the channel member 12 so that it will be held firmly in place therein. The channel 12 in addition to supporting the tube 17 also operates to limit the amount of collapsing of the tube 17 by the wheels of the vehicles passing thereover. The tube and channel are relatively narrow as compared to the diameters of the vehicle wheels passing thereover, so that the vehicle wheels are at all times supported by the pavement and thechannel. The vehicle weightis nevei' pla ced entirely upon the tube so that damage to the tube and its contents is at all times effectively prevented. i V

While the detector of this invention m ay have any desired dimensions particularly satisfactory dimensions are as follows: overall width of channel member 1% inch, overall height of channel member /2 inch, overall width of tube .930 inch, overall heightof tube AlS inch, thickness of fingers .045 inch.

While for purposes of illustration one form of this invention has been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure, and, therefore, this invention is to be limited only by the scope of the appended claims,

I claim as my invention:

l. A detector for highway vehicle traflic comprisingjan upwardly facing channel member imbeddedin aftransverse groove in the highway, a hollow tube, ofrflexible resilient electrical insulating material located in the channel member and having side and bottom, walls corresponding to the configuration of the channel member and a top wall protruding above the channel member to be contacted and depressed by the wheels of thetvehicles passingthereover, said hollow tube of flexible resilient insulating material having integrally formed inwardly thereof a pair of opposed downwardly facing shoulders, a pair of opposed inwardly and upwardly extending fingers above the shoulders and a pair of opposed-inwardly and upwardly extending fingers below the shoulders, an upper metallic contact strip interposed between the top wall and the upper fingers and maintained adjacent the top wall by the upper fingers, a lower metallic contact strip interposed between the shoulders and the lower fingers and normally maintained against theishoulders by the lower fingers, said contact strips being normally spaced apart, said upper contact strip being moved downwardly into engagement with the lower contact strip when the top wall of the tube is depressed by the wheels of the vehicles passing thereover to establish an electrical contact between the contact strips, and the lower contact strip being moved downwardly by the upper contact strip when engaged thereby to prevent damage to the contact strips. 7 a

2. A detector for highway vehicle traflic comprising an upwardly facing channel member imbedded in a transverse groove in the highway, a hollow tube of flexibletresilient electrical insulating material located in the channel member and having side and bottom walls corresponding to the configuration of the channel member and a top wall protruding above the channel member to be contacted and depressed by the wheels of the vehicles passing there over, said hollow tube of flexible resilient insulating material having integrally formed inwardly thereof alpair of opposed downwardly facing shoulders, a pair of opposed inwardly and upwardly extending fingers above the shoulders and a pair of opposed inwardly and upwardly extending fingers below the shoulders, an upper metallic contact strip interposed between the top wall and the upper fingers and maintained adjacent the'top wall by the upper fingers, a lower metallic contact strip interposed between the shoulders and the lower fingers and normally maintained against thelshoulde rs by the'lower fingersja plurality of downwardly extending contacts carried by the upper contact strip, a plurality of upwardly extending contacts carried by the lowercontact strip in vertical alignment with the contacts or the upper contact strip, said contacts of the upper contact strip beingnormally spa ced from the contacts of the lower contact strip, said contacts of the upper contact strip being moved downwardly into engagement with the contacts of the lower contact strip when the top wall of the tube isdepressed by the wheelsof the vehicles passing thereover to establish an electrical contact therebetween, and the lower contact strip being moved downwardly by the upper contact strip when the contacts thereof are engaged by the contacts of the upper contact strip to prevent damage to the contacts and the contact strips.

3. In a detector for highway vehicle traflic, a hollow tube of flexible resilient electrical insulating material having side and bottom .walls and a top Wall to be contacted and depressed by the wheels of the vehicles passing thereover, said hollow tube of flexible resilient insulating material having integrally formed inwardly thereof a pair of opposed downwardly facing shoulders, a pair of opposed inwardly and upwardly extending fingers above the shoulders and a pair of opposed inwardly and upwardly extending fingers below the shoulders, an upper metallic contact strip interposed between the top wall and the upper fingers and maintained adjacent the top wall by the upper fingers, a lower metallic contact strip interposed between the shoulders and the "lower fingers and normally maintained against the shouldersby the lower fingers, said contact' s trips being normallyspaced apart, said upper contact strip being moved downwardly into engagement with the lowereontact strip when the top wall or" the tube is depressed by the wheels of the vehicleslpassing thereover to establish an electrical contact between the contact strips, and the lower contact strip being moved downwardly by the uppe r contact etrip when engaged thereby to prevent damage to theicontact strips.

4. Inf'a detector forhighwayyehicle' tra ffiga hollow tube of flexible resilient electrical insulating .material having side and bottom pwallsand a topwall to be contacted and depressed by the wheels of the vehicles passing thereover, said hollow tube of flexible resilient insulating material having in tegr ally formed inwardlythereof a pair of opposed downwardly facing shoulders, a pair of opposed inwardly and upwardly extending fingers above the shoulders and a pair of opposed inwardly and upwardly extending fingers below the shoulders, an ppper metallic contact strip interposed between the top 'wall andv the upper fingers and maintained adjacent the top wall by the upper fingers, a lower metallic contact strip interposed between the shouldersand the'lo wer fingers and normally maintained against the shoulders by the lower fingers, a plurality of downwardlyextending contacts carried by the upper contact strip, a plurality of .upwardly extending contacts carried by the lower contact strip in vertical alignment with the contacts of the upper contact strip, said contacts of the upper contact strip being normally spaced from the contacts of the lower contactstrip, said contacts of the uppef contact strip being moved downwardly into engagement with the contacts of the lower contact strip when the top wall of the tube is depressed by the Wheels of the'vehicles passing thereover to establish an electrical contact therebetween, and the lower contact strip being moved downwardly by the upper contact strip when the contacts thereof are engaged by the contacts of the upper contact strip to prevent damage to the contacts and the contact strips.

5. A dectector for highw ay vehicle traffic comprising an upwardly facing channel member imbedded in a transverse groove in the highway, a hollow tube of flexible resilient electrical'insi rlating material located in the channel member and having side and bottom walls corresponding to the configuration'of the channel member and a top wall protruding above the channel member to be contacted and depressed'by. the wheels of the vehicles passing thereover, an upper'metallic contact strip'longitudinally arranged in the hollow'tube adjacent the top wall thereof, a lower metallic contact strip longitudinally arranged in the hollow tube adjacent the bottom wall thereof, a pair of opposed flexible resilient fingers extending inwardly and upwardly'from-the side walls of the hollowtube between the upper and'lower' contact strips for normally maintaining said contact strips'spaced apart, said upper contact strip being moved downwardly against the action of the fingers to cause electrical contact with the lower contact strip when the top wall of the tube is depressed by the wheels of the vehicles passing thereover.

6. A detector for highway vehicle traflic comprising an upwardly facing channel member imbedded in a transverse groove in the highway, a hollow tube of flexible resilient electrical insulating material located in the channel member and having side and bottom walls corresponding to the configuration of the channel member and a top wall protruding above the channel member to be contacted and depressed by the wheels of the vehicles passing thereover, an upper metallic contact strip longitudinally arranged in the hollow tube adjacent the top wall thereof, a lower metallic contact strip longitudinally arranged in the hollow tube adjacent the bottom wall thereof, a plurality of contacts carried by the contact strips, a pair of opposed flexible resilient fingers extending inwardly and upwardly from the side walls of the hollow tube between the upper and lower contact strips for normally maintaining the contacts on the contact strips spaced apart, said upper contact strip being moved downwardly against the action of the fingers to cause engagement of the contacts on the contact strips when the top wall of the tube is depressed by the wheels of the vehicles passing thereover.

7. In a detector for highway vehicle traffic, a hollow tube of flexible resilient electrical insulating material having side and bottom walls and a top wall to be contacted and depressed by the wheels of the vehicles passing thereover, an upper metallic contact strip longitudinally arranged in the hollow tube adjacent the top wall thereof, a lower metallic contact strip longitudinally arranged in the hollow tube adjacent the bottom wall there of, a pair of opposed flexible resilient fingers extending inwardly and upwardly from the side walls of the hollow tube between the upper and lower contact strips for normally maintaining said contact strips spaced apart, said upper contact strip being moved downwardly against the action of the fingers to cause electrical contact with the lower contact strip when the top wall of the tube is depressed by the wheels of the vehicles passing thereover.

8. In a detector for highway vehicle traflic, a hollow tube of flexible resilient electrical insulating material having side and bottom walls and a top wall to be contacted and depressed by the wheels of the vehicles passing thereover, an upper metallic contact strip longitudinally arranged in the hollow tube adjacent the top wall thereof, a lower metallic contact strip longitudinally arranged in the hollow tube adjacent the bottom wall thereof, a plurality of contacts carried by the contact strips, a pair of opposed flexible resilient fingers extending inwardly and upwardly from the side walls of the hollow tube between the upper and lower contact strips for normally maintaining the contacts on the contact strips spaced apart, said upper contact strip being moved downwardly against the action of the fingers to cause engagement of the contacts on the contact strips when the top wall of the tube is depressed by the wheels of the vehicles passing thereover.

9. In a detector for highway vehicle trafiic, a hollow tube of flexible resilient electrical insulating material having side and bottom walls and a top wall to be contacted and depressed by the wheels of the vehicles passing thereover, an upper metallic contact strip longitudinally arranged in the hollow tube, a lower metallic contact strip longitudinally arranged in the hollow tube, a first pair of opposed flexible resilient fingers extending inwardly and upwardly from the side walls of the hollow tube between the upper and lower contact strips for maintaining the upper contact strip against the top wall of the hollow tube and for normally maintaining the upper and lower contact strips spaced apart, a second pair of opposed flexible resilient fingers extending inwardly and upwardly from the side walls below .the lower contact strip for normally spacing the lower contact strip from the bottom wall of the hollow tube, said upper contact strip being moved downwardly against the action of the first pair of fingers to cause electrical contact with the lower contact strip when the top wall of the tube is depressed by the wheels of the vehicles passing thereover, and the lower contact strip being moved downwardly against the action of the second pair of fingers by the upper contact strip when electrically contacted thereby to prevent damage to the contact strips.

10. In a detector for highway vehicle traflic, a hollow tube of flexible resilient electrical insulating material having side and bottom walls and a top wall to be contacted and depressed by the wheels of the vehicles passing thereover, an upper metallic contact strip longitudinally arranged in the hollow tube, a lower metallic contact strip longitudinally arranged in the hollow tube, a plurality of contacts carried by the contact strips, a first pair of opposed flexible resilient fingers extending inwardly and upwardly from the side walls of the hollow tube between the upper and lower contact strips for maintaining the upper contact strip against the top wall of the hollow tube and for normally maintaining the contacts on the contact strips spaced apart, a second pair of opposed flexible resilient fingers extending inwardly and upwardly from the side walls below the lower contact strip for normally spacing the lower contact strip from the bottom wall of the hollow tube, said upper contact strip being moved downwardly against the action of the first pair of fingers to cause engagement of the contacts on the contact strips when the top wall of the tube is depressed by the wheels of the vehicles passing thereover, and the lower contact strip being moved downwardly against the action of the second pair of fingers by the upper contact strip when the contacts are engaged to prevent damage to the contacts and contact strips.

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